This invention relates to a cone crusher for crushing stones and the like.
As is known, long shaft cone crushers comprise essentially an outer shroud formed of two pieces, namely a bottom shroud and top shroud, which are connected to each other by means of strong bolts which allow the material to flow from top to bottom.
The shroud has mounted internally a suspended or supported shaft which undergoes an eccentric movement at the lower portion thereof, thereby the shaft performs a conical swinging movement.
At a middle portion of the shaft, there is provided a conical part, called the crushing cone, which widens out from top to bottom and is located at a conical milling ring provided on the shroud inside.
The conical milling ring has a smaller taper than the milling or crushing cone, such that the space or clearance between the cone and ring widens towards the top.
Moreover, cone crushers are equipped with devices for raising and lowering the crushing cone with respect to the crushing ring in order to increase or decrease the space separating the cone from the ring and thus throttle the passage area and consequently the size of the resulting product.
The most critical operation of conventional crushers is in fact, and in general, the cone height adjustment, which is accomplished by hydraulic power. More precisely, the shaft carrying the crushing stone floats on a pressurized oil cushion which constitutes the fixed hydraulic raising group, a set of bevel gears being provided within the machine along with a countershaft driving the cam which imparts to the shaft bottom portion the desired eccentric rotation which provides the cited conical swinging movement.
In addition to the above, seating or the like means must be provided for supporting the bottom portion of the shaft and withstand the axial push, which means are unavoidable subjected to a fast wear rate owing to the continuous oscillation of the shaft bottom or lower end.